Hearthpwn

The goal is to behave like a non-discard Zoo deck up until Hemet, Jungle Hunter is drawn, which will then shift gears into the deck's Combo. Ideally you want to get rid of all 3-cost or lower minions remaining minions in your hand the turn before you play Hemet, Jungle Hunter, thereby giving you the best chance to discard 1 of the 2 Cruel Dinomancers when Doomguard is played the turn following Hemet. Once a Dinomancer has been discarded-- and has been the ONLY minion to be discarded-- you are then free to set up the Spiritsinger Umbra + Cruel Dinomancer endgame combo that fills the board with immortal 5/5's. Unless your opponent can still silence them all, this should win the game-- Assuming he's not already about to kill you.

The deck only has 1 Doomguard to prevent keeping detrimental targets after Hemet cleans out the deck. Assuming you are able to arrange a hand that has only one Cruel Dinomancer and possibly some leftover spells, you should hopefully be able to use Doomguard to discard the Dimomancer. However, in the event that you miss the Dinomancer, it would help to also have at least 1 Soulfire to use as a backup (and pray that it wasn't one of the cards discarded!).

During the "Zoo stage," if the opportunity arises that you can empty out your hand except for a drawn Dinomancer and a Soulfire/Doomgouard, then this will take care of the "hard part" early, and just play Hemet.

Otherwise you'll actually want to wait until Turn 8 to play Hemet, even if you nab him earlier on. In order for the Dinomancer-Umbra combo to work reliably, you will need to play both cards on the same turn with 10 Mana, otherwise you will draw the combo pieces on turns 7-10 without a means of playing the cards properly. Ideally, you will want Doomguard/Soulfire and Hemet on turn 8 and play Hemet --> Draw a Dinomancer Turn 9 and discard it with Doomguard/Soulfire + tap to draw 1 of the last 2 cards of the deck (which should either be the second Dinomancer, or the Umbra) --> Draw the last card of the deck and play Umbra, followed by the second Dinomancer. You will also want to wait until turn 9 to play Doomguard just in case the card you draw into happens to be Spiritsinger Umbra, so that way you are able to play both cards and not discard the Umbra.

It is also worth mentioning that you NEVER want to keep Umbra in your opening hand. You want to draw into Umbra as one of your last 2 cards, otherwise you run the risk of discarding Umbra.

Update 1.3: With the new Unwilling Sacrifice and Defile you now have greater removal and clear tools that doesn't interfere with the Hemet Combo.